Republicans in the Senate are sending warnings to President Trump that they will push back on his national emergency declaration to build a border wall if he doesn’t withdraw it.

As of Thursday evening, three Republican senators had said they would support the House-passed resolution rejecting the emergency. If four Republicans voted with all Democrats, the resolution would pass in the Senate, too.

Sen. Lamar Alexander (R-Tenn.), who is retiring, did not say Thursday whether he would be that fourth vote but pointed to money already available to be used for the wall without diverting military construction funds.

“He’s got sufficient funding without a national emergency,” Alexander told reporters, according to Politico. “He can build a wall and avoid a dangerous precedent.”

Besides the three who have announced their support of the House joint resolution – Sens. Susan Collins (R-Maine), Lisa Murkowski (R-Alaska) and Thom Tillis (R-N.C.) – most GOP senators have remained noncommittal.

“I have long believed and advocated that every president, Republican and Democrat, should act consistent with the Constitution and federal law,” Sen. Ted Cruz (R-Texas) said, according to Politico. “And I’m assessing those legal authorities right now.”